In the Garden:Western Mountains and High Plains
December, 2007
Regional Report

Growing Herbs Indoors

Even though cold weather is here and it's a bit bleak outdoors, you can still enjoy fresh herbs indoors. You don't need a fancy greenhouse. There are many compact types of culinary herbs that can be grown in your home to provide fresh spicy flavor to your winter dishes.

The trick to growing herbs inside is providing the right environment -- the amount of light, water, fertilizer, and humidity needed by the different herbs. Healthy herb plants double as decorative houseplants, too.

Light
The amount of sunlight or supplemental light your plants receive will dictate what kinds of herbs you can grow. In a sunny, south- or southwest-facing windowsill, try growing sage, rosemary, thyme, and even spicy-tasting nasturtiums. The east- or west-facing windows will do nicely for aromatic mints, chives, parsley, and old-fashioned scented geraniums.

Now if you don't have enough natural sunlight, don't fret. Herbs can be grown under grow lights. It's important to set a timer on the light fixture to ensure that the herbs get 12 to 14 hours of light per day. Lack of adequate light results in thin, small leaves. Leaves receiving proper light will be thick and normal in size.

Watering
Most herbs are sensitive to overwatering or soggy soils. Check the moisture by pressing your finger into the top inch of potting mix. If you can detect moisture, don't water. When the soil is dry to the touch, water until the excess drains from the bottom of the pot. Throw away the excess or leave it in the pebble tray as long as the container is not sitting directly in the water.

Fertilizer
To grow herbs with more intense flavor, be stingy with the fertilizer. Only fertilize when the potting mixture is damp, never dry. I like to use a soluble plant food diluted at half the recommended rate.

Humidity
One of the most important elements to growing herbs is ample humidity, perhaps even more so at this time of year since our forced-air heating systems rob the air of needed humidity. Dry air not only dries out our skin, it can cause houseplants to develop brown or dry tips. I've found that placing newly purchased potted herbs on trays or saucers filled with pebbles and water will help ensure their success indoors. Just be sure that the pots themselves are not sitting directly in water, as this can lead to root rot.

Use a little fan to circulate the air and help discourage fungal diseases such as powdery mildew.